// SPDX-License-Identifier: GPL-2.0+ /* NetworkManager -- Network link manager * * Copyright (C) 2007 - 2013 Red Hat, Inc. */ #include "nm-default.h" #include #include #include #include "nm-utils/nm-vpn-plugin-macros.h" #include "nm-dhcp-helper-api.h" /*****************************************************************************/ #if NM_MORE_LOGGING #define _NMLOG_ENABLED(level) TRUE #else #define _NMLOG_ENABLED(level) ((level) <= LOG_ERR) #endif #define _NMLOG(always_enabled, level, ...) \ G_STMT_START { \ if ((always_enabled) || _NMLOG_ENABLED (level)) { \ GTimeVal _tv; \ \ g_get_current_time (&_tv); \ g_print ("nm-dhcp-helper[%ld] %-7s [%ld.%04ld] " _NM_UTILS_MACRO_FIRST (__VA_ARGS__) "\n", \ (long) getpid (), \ nm_utils_syslog_to_str (level), \ _tv.tv_sec, _tv.tv_usec / 100 \ _NM_UTILS_MACRO_REST (__VA_ARGS__)); \ } \ } G_STMT_END #define _LOGD(...) _NMLOG(TRUE, LOG_INFO, __VA_ARGS__) #define _LOGI(...) _NMLOG(TRUE, LOG_NOTICE, __VA_ARGS__) #define _LOGW(...) _NMLOG(TRUE, LOG_WARNING, __VA_ARGS__) #define _LOGE(...) _NMLOG(TRUE, LOG_ERR, __VA_ARGS__) #define _LOGd(...) _NMLOG(FALSE, LOG_INFO, __VA_ARGS__) #define _LOGi(...) _NMLOG(FALSE, LOG_NOTICE, __VA_ARGS__) #define _LOGw(...) _NMLOG(FALSE, LOG_WARNING, __VA_ARGS__) /*****************************************************************************/ static const char * ignore[] = {"PATH", "SHLVL", "_", "PWD", "dhc_dbus", NULL}; static GVariant * build_signal_parameters (void) { char **item; GVariantBuilder builder; g_variant_builder_init (&builder, G_VARIANT_TYPE_VARDICT); /* List environment and format for dbus dict */ for (item = environ; *item; item++) { char *name, *val, **p; /* Split on the = */ name = g_strdup (*item); val = strchr (name, '='); if (!val || val == name) goto next; *val++ = '\0'; /* Ignore non-DCHP-related environment variables */ for (p = (char **) ignore; *p; p++) { if (strncmp (name, *p, strlen (*p)) == 0) goto next; } /* Value passed as a byte array rather than a string, because there are * no character encoding guarantees with DHCP, and D-Bus requires * strings to be UTF-8. * * Note that we can't use g_variant_new_bytestring() here, because that * includes the trailing '\0'. (??!?) */ g_variant_builder_add (&builder, "{sv}", name, g_variant_new_fixed_array (G_VARIANT_TYPE_BYTE, val, strlen (val), 1)); next: g_free (name); } return g_variant_ref_sink (g_variant_new ("(a{sv})", &builder)); } static void kill_pid (void) { const char *pid_str; pid_t pid = 0; pid_str = getenv ("pid"); if (pid_str) pid = strtol (pid_str, NULL, 10); if (pid) { _LOGI ("a fatal error occurred, kill dhclient instance with pid %d", pid); kill (pid, SIGTERM); } } int main (int argc, char *argv[]) { gs_unref_object GDBusConnection *connection = NULL; gs_free_error GError *error = NULL; gs_unref_variant GVariant *parameters = NULL; gs_unref_variant GVariant *result = NULL; gboolean success = FALSE; guint try_count = 0; gint64 time_end; /* FIXME: g_dbus_connection_new_for_address_sync() tries to connect to the socket in * non-blocking mode, which can easily fail with EAGAIN, causing the creation of the * socket to fail with "Could not connect: Resource temporarily unavailable". * * We should instead create the GIOStream ourself and block on connecting to * the socket. */ connection = g_dbus_connection_new_for_address_sync ("unix:path=" NMRUNDIR "/private-dhcp", G_DBUS_CONNECTION_FLAGS_AUTHENTICATION_CLIENT, NULL, NULL, &error); if (!connection) { g_dbus_error_strip_remote_error (error); _LOGE ("could not connect to NetworkManager D-Bus socket: %s", error->message); goto out; } parameters = build_signal_parameters (); time_end = g_get_monotonic_time () + (200 * 1000L); /* retry for at most 200 milliseconds */ do_notify: try_count++; result = g_dbus_connection_call_sync (connection, NULL, NM_DHCP_HELPER_SERVER_OBJECT_PATH, NM_DHCP_HELPER_SERVER_INTERFACE_NAME, NM_DHCP_HELPER_SERVER_METHOD_NOTIFY, parameters, NULL, G_DBUS_CALL_FLAGS_NONE, 1000, NULL, &error); if (!result) { gs_free char *s_err = NULL; s_err = g_dbus_error_get_remote_error (error); if (NM_IN_STRSET (s_err, "org.freedesktop.DBus.Error.UnknownMethod")) { gint64 remaining_time = time_end - g_get_monotonic_time (); /* I am not sure that a race can actually happen, as we register the object * on the server side during GDBusServer:new-connection signal. * * However, there was also a race for subscribing to an event, so let's just * do some retry. */ if (remaining_time > 0) { _LOGi ("failure to call notify: %s (retry %u)", error->message, try_count); g_usleep (NM_MIN (NM_CLAMP ((gint64) (100L * (1L << try_count)), 5000, 25000), remaining_time)); g_clear_error (&error); goto do_notify; } } _LOGW ("failure to call notify: %s (try signal via Event)", error->message); g_clear_error (&error); /* for backward compatibility, try to emit the signal. There is no stable * API between the dhcp-helper and NetworkManager. However, while upgrading * the NetworkManager package, a newer helper might want to notify an * older server, which still uses the "Event". */ if (!g_dbus_connection_emit_signal (connection, NULL, "/", NM_DHCP_CLIENT_DBUS_IFACE, "Event", parameters, &error)) { g_dbus_error_strip_remote_error (error); _LOGE ("could not send DHCP Event signal: %s", error->message); goto out; } /* We were able to send the asynchronous Event. Consider that a success. */ success = TRUE; } else success = TRUE; if (!g_dbus_connection_flush_sync (connection, NULL, &error)) { g_dbus_error_strip_remote_error (error); _LOGE ("could not flush D-Bus connection: %s", error->message); success = FALSE; goto out; } out: if (!success) kill_pid (); return success ? EXIT_SUCCESS : EXIT_FAILURE; }